Will the computer and wiring harness from a 1991, 2WD 22RE work for a 1989, 4wd 22RE? If not, what is the difference? I am an instrumentation tech by day and I can probably make it work if I can identify a specific difference.

 

Dont hold me to it but they should be the same. I just went through the same thing but my motor was 85-87 in a 89. And I ended up buying a wiring harness from a 91. Only thing you might want to find out for sure is about the 4x4. Dont know what that would change in the ecu. I think all you have to do on the wiring harness is cut and splice in the plug.

 

my guess is it would work, just try an match 5 spd or auto. maybe the 4wd light wont work?

 

I know some of the 2wd 22re's didn't have knock sensors so that could create issues

 

my biggest concern is injector pulse duration. If that's the case it SHOULD just run rich or lean. Hopefully I won't run into that and if I do and thats the only issue, at least I will know I have a good computer. Then all I have to do is get the ECU flashed for the right timing and fuel curves. The knock sensor and 4wd light can suck it!! As long as i can get it to run right until next winter. Her legally tagged days are pretty much over anyway.

 

open the case and check the pinout.

probs only difference is a more refined tune on the newer ECU

 

Overall, no.
A 2wd ECU is not compatible with a 4WD truck. The 2wd does not monitor things like "4WD" and such.
IIRC, the 91 2wd is electronic speedo and the 89 is mechanical.

I'm not going to say you can't make it work but it won't be easy.

Then again, if you're pluggin a 91 ECU and harness in an 89 truck... you might have to do other things to make the 89 truck pass 91 emissions / smog.

 

Im pretty sure my ecu from an 86' Corona has the 4x4 pins, even though its a 2wd

Do you really know what each pin really does?

 

I don't understand why you want to do this in the first place. Don't get me wrong I understand saving on money if you already have one but just find a harness for that year and save the headache. On the other side it won't take long to install the harness maybe just plug it all in and give it a try.